From cadf1ccf1b0021d0b7a9347e102ac5258f9f98c8 Mon Sep 17 00:00:00 2001 From: Gao Xiang Date: Tue, 21 Aug 2018 22:49:31 +0800 Subject: [PATCH] staging: erofs: add error handling for xattr submodule This patch enhances the missing error handling code for xattr submodule, which improves the stability for the rare cases. Signed-off-by: Gao Xiang Reviewed-by: Chao Yu Signed-off-by: Chao Yu Signed-off-by: Greg Kroah-Hartman --- drivers/staging/erofs/internal.h | 6 +- drivers/staging/erofs/xattr.c | 122 ++++++++++++++++++++++++++------------- 2 files changed, 85 insertions(+), 43 deletions(-) diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h index a756abe..8951e01 100644 --- a/drivers/staging/erofs/internal.h +++ b/drivers/staging/erofs/internal.h @@ -485,10 +485,10 @@ struct erofs_map_blocks_iter { static inline struct page * -erofs_get_inline_page_nofail(struct inode *inode, - erofs_blk_t blkaddr) +erofs_get_inline_page(struct inode *inode, + erofs_blk_t blkaddr) { - return erofs_get_meta_page_nofail(inode->i_sb, + return erofs_get_meta_page(inode->i_sb, blkaddr, S_ISDIR(inode->i_mode)); } diff --git a/drivers/staging/erofs/xattr.c b/drivers/staging/erofs/xattr.c index 2593c85..79d7fc8 100644 --- a/drivers/staging/erofs/xattr.c +++ b/drivers/staging/erofs/xattr.c @@ -24,16 +24,25 @@ struct xattr_iter { static inline void xattr_iter_end(struct xattr_iter *it, bool atomic) { - /* only init_inode_xattrs use non-atomic once */ + /* the only user of kunmap() is 'init_inode_xattrs' */ if (unlikely(!atomic)) kunmap(it->page); else kunmap_atomic(it->kaddr); + unlock_page(it->page); put_page(it->page); } -static void init_inode_xattrs(struct inode *inode) +static inline void xattr_iter_end_final(struct xattr_iter *it) +{ + if (it->page == NULL) + return; + + xattr_iter_end(it, true); +} + +static int init_inode_xattrs(struct inode *inode) { struct xattr_iter it; unsigned i; @@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode) bool atomic_map; if (likely(inode_has_inited_xattr(inode))) - return; + return 0; vi = EROFS_V(inode); BUG_ON(!vi->xattr_isize); @@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode) it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize); it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize); - it.page = erofs_get_inline_page_nofail(inode, it.blkaddr); - BUG_ON(IS_ERR(it.page)); + it.page = erofs_get_inline_page(inode, it.blkaddr); + if (IS_ERR(it.page)) + return PTR_ERR(it.page); /* read in shared xattr array (non-atomic, see kmalloc below) */ it.kaddr = kmap(it.page); @@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode) ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs); vi->xattr_shared_count = ih->h_shared_count; - vi->xattr_shared_xattrs = (unsigned *)kmalloc_array( - vi->xattr_shared_count, sizeof(unsigned), - GFP_KERNEL | __GFP_NOFAIL); + vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count, + sizeof(uint), GFP_KERNEL); + if (vi->xattr_shared_xattrs == NULL) { + xattr_iter_end(&it, atomic_map); + return -ENOMEM; + } /* let's skip ibody header */ it.ofs += sizeof(struct erofs_xattr_ibody_header); @@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode) BUG_ON(it.ofs != EROFS_BLKSIZ); xattr_iter_end(&it, atomic_map); - it.page = erofs_get_meta_page_nofail(sb, + it.page = erofs_get_meta_page(sb, ++it.blkaddr, S_ISDIR(inode->i_mode)); - BUG_ON(IS_ERR(it.page)); + if (IS_ERR(it.page)) + return PTR_ERR(it.page); it.kaddr = kmap_atomic(it.page); atomic_map = true; @@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode) xattr_iter_end(&it, atomic_map); inode_set_inited_xattr(inode); + return 0; } struct xattr_iter_handlers { @@ -101,19 +116,26 @@ struct xattr_iter_handlers { void (*value)(struct xattr_iter *, unsigned, char *, unsigned); }; -static void xattr_iter_fixup(struct xattr_iter *it) +static inline int xattr_iter_fixup(struct xattr_iter *it) { - if (unlikely(it->ofs >= EROFS_BLKSIZ)) { - xattr_iter_end(it, true); + if (it->ofs < EROFS_BLKSIZ) + return 0; + + xattr_iter_end(it, true); - it->blkaddr += erofs_blknr(it->ofs); - it->page = erofs_get_meta_page_nofail(it->sb, - it->blkaddr, false); - BUG_ON(IS_ERR(it->page)); + it->blkaddr += erofs_blknr(it->ofs); - it->kaddr = kmap_atomic(it->page); - it->ofs = erofs_blkoff(it->ofs); + it->page = erofs_get_meta_page(it->sb, it->blkaddr, false); + if (IS_ERR(it->page)) { + int err = PTR_ERR(it->page); + + it->page = NULL; + return err; } + + it->kaddr = kmap_atomic(it->page); + it->ofs = erofs_blkoff(it->ofs); + return 0; } static int inline_xattr_iter_begin(struct xattr_iter *it, @@ -134,22 +156,25 @@ static int inline_xattr_iter_begin(struct xattr_iter *it, it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs); it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs); - it->page = erofs_get_inline_page_nofail(inode, it->blkaddr); - BUG_ON(IS_ERR(it->page)); - it->kaddr = kmap_atomic(it->page); + it->page = erofs_get_inline_page(inode, it->blkaddr); + if (IS_ERR(it->page)) + return PTR_ERR(it->page); + it->kaddr = kmap_atomic(it->page); return vi->xattr_isize - xattr_header_sz; } static int xattr_foreach(struct xattr_iter *it, - struct xattr_iter_handlers *op, unsigned *tlimit) + const struct xattr_iter_handlers *op, unsigned int *tlimit) { struct erofs_xattr_entry entry; unsigned value_sz, processed, slice; int err; /* 0. fixup blkaddr, ofs, ipage */ - xattr_iter_fixup(it); + err = xattr_iter_fixup(it); + if (err) + return err; /* * 1. read xattr entry to the memory, @@ -181,7 +206,9 @@ static int xattr_foreach(struct xattr_iter *it, if (it->ofs >= EROFS_BLKSIZ) { BUG_ON(it->ofs > EROFS_BLKSIZ); - xattr_iter_fixup(it); + err = xattr_iter_fixup(it); + if (err) + goto out; it->ofs = 0; } @@ -213,7 +240,10 @@ static int xattr_foreach(struct xattr_iter *it, while (processed < value_sz) { if (it->ofs >= EROFS_BLKSIZ) { BUG_ON(it->ofs > EROFS_BLKSIZ); - xattr_iter_fixup(it); + + err = xattr_iter_fixup(it); + if (err) + goto out; it->ofs = 0; } @@ -273,7 +303,7 @@ static void xattr_copyvalue(struct xattr_iter *_it, memcpy(it->buffer + processed, buf, len); } -static struct xattr_iter_handlers find_xattr_handlers = { +static const struct xattr_iter_handlers find_xattr_handlers = { .entry = xattr_entrymatch, .name = xattr_namematch, .alloc_buffer = xattr_checkbuffer, @@ -294,8 +324,11 @@ static int inline_getxattr(struct inode *inode, struct getxattr_iter *it) ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining); if (ret >= 0) break; + + if (ret != -ENOATTR) /* -ENOMEM, -EIO, etc. */ + break; } - xattr_iter_end(&it->it, true); + xattr_iter_end_final(&it->it); return ret < 0 ? ret : it->buffer_size; } @@ -318,9 +351,10 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it) if (i) xattr_iter_end(&it->it, true); - it->it.page = erofs_get_meta_page_nofail(sb, - blkaddr, false); - BUG_ON(IS_ERR(it->it.page)); + it->it.page = erofs_get_meta_page(sb, blkaddr, false); + if (IS_ERR(it->it.page)) + return PTR_ERR(it->it.page); + it->it.kaddr = kmap_atomic(it->it.page); it->it.blkaddr = blkaddr; } @@ -328,9 +362,12 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it) ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL); if (ret >= 0) break; + + if (ret != -ENOATTR) /* -ENOMEM, -EIO, etc. */ + break; } if (vi->xattr_shared_count) - xattr_iter_end(&it->it, true); + xattr_iter_end_final(&it->it); return ret < 0 ? ret : it->buffer_size; } @@ -355,7 +392,9 @@ int erofs_getxattr(struct inode *inode, int index, if (unlikely(name == NULL)) return -EINVAL; - init_inode_xattrs(inode); + ret = init_inode_xattrs(inode); + if (ret) + return ret; it.index = index; @@ -498,7 +537,7 @@ static int xattr_skipvalue(struct xattr_iter *_it, return 1; } -static struct xattr_iter_handlers list_xattr_handlers = { +static const struct xattr_iter_handlers list_xattr_handlers = { .entry = xattr_entrylist, .name = xattr_namelist, .alloc_buffer = xattr_skipvalue, @@ -520,7 +559,7 @@ static int inline_listxattr(struct listxattr_iter *it) if (ret < 0) break; } - xattr_iter_end(&it->it, true); + xattr_iter_end_final(&it->it); return ret < 0 ? ret : it->buffer_ofs; } @@ -542,9 +581,10 @@ static int shared_listxattr(struct listxattr_iter *it) if (i) xattr_iter_end(&it->it, true); - it->it.page = erofs_get_meta_page_nofail(sb, - blkaddr, false); - BUG_ON(IS_ERR(it->it.page)); + it->it.page = erofs_get_meta_page(sb, blkaddr, false); + if (IS_ERR(it->it.page)) + return PTR_ERR(it->it.page); + it->it.kaddr = kmap_atomic(it->it.page); it->it.blkaddr = blkaddr; } @@ -554,7 +594,7 @@ static int shared_listxattr(struct listxattr_iter *it) break; } if (vi->xattr_shared_count) - xattr_iter_end(&it->it, true); + xattr_iter_end_final(&it->it); return ret < 0 ? ret : it->buffer_ofs; } @@ -565,7 +605,9 @@ ssize_t erofs_listxattr(struct dentry *dentry, int ret; struct listxattr_iter it; - init_inode_xattrs(d_inode(dentry)); + ret = init_inode_xattrs(d_inode(dentry)); + if (ret) + return ret; it.dentry = dentry; it.buffer = buffer; -- 2.7.4